The long-accepted narrative concerning mankind's spread throughout the globe from Africa is now being challenged by fossils discovered in China.
Fossil teeth of modern humans dug out of the Daoxian province in south China date to 80,000 years ago. This is 20,000 years ahead of the originally supposed successful migration of humankind out of Africa.
This find has so shaken perceptions that the possiblity of more than one hegira out of Africa must be considered. Dr María Martinón-Torres of the University College of London (UCL) emphasises the need to re-think existing models.
A bevy of evidence from the archeological and genetic standpoint served as the framework for the model of mankind's migration from Africa 60,000 years ago.
The early humans who lived in the horn of Africa were said to have travelled across the Red Sea through the Bab el Mandeb straits. Low water levels in that time made this journey possible. All peoples, even the non-African peoples, were posited to be products of this migration.
As BBC reports, Dr Maria Martinon-Torres cited that based on careful analysis the discovered fossil teeth clearly belonged to modern humans. This made the date of the fossil very surprising. The teeth were found sealed in a gravestone-line calcitic floor and would have to have been older than the sealing layer.
This signifies that because everything found below these stalagmites are likely older than 80,000 years old, the fossil human teeth may as old as 125,000 years. Radioactive dating categorised the animal fossils, which were discovered with the human teeth, to be typically Late Pleistocene.
Fossils from earlier than the 'Out of Africa' migration discovered in the Skhul and Qafzeh caves of Israel have always been regarded as earlier and failed attempts at migration. The modern humans who participated in these attempts were thought to have gone extinct. Such conclusion is now enveloped by a cloud of doubt because of the Daoxian finds.
Professor Chris Stringer of London's Natural History Museum labels this new study as a veritable "game-changer".
"Many workers (often including me) have argued that the early dispersal of modern humans from Africa into the Levant recorded by the fossils from Skhul and Qafzeh at about 120,000 years ago was essentially a failed dispersal which went little or no further than Israel."
Professor Stinger continues, "However, the large sample of teeth from Daoxian seem unquestionably modern in their size and morphology, and they look to be well-dated by uranium-thorium methods to at least 80,000 years. At first sight this seems to be consistent with an early dispersal across southern Asia by a population resembling those known from Skhul and Qafzeh."
"But the Daoxian fossils resemble recent human teeth much more than they look like those from Skhul and Qafzeh, which retain more primitive traits. So either there must have been rapid evolution of the dentitions of a Skhul-Qafzeh type population in Asia by about 80,000 years, or the Daoxian teeth represent a hitherto-unsuspected early and separate dispersal of more modern-looking humans."
